The following link is to the blog Gunpowder Woodworks and in it Mark Hockstein demonstrates a very quick and accurate way to cut the buttons that attach a table top to the apron. He got the idea from Chuck Bender of Acanthus Workshop. Mark's post is titled "Why You Should Take Classes From Master Cabinetmakers", and I can attest that the reasons he gives are very true. When you take a class from a master, you pick up so many incidental tips that are priceless.
Check out the video, as I am interested if others find it a great way to make these buttons.